As demonstrated in Table REF  (Appendix), sequential training has lower concept error but worse task performance as compared to joint training (Consistently shown by Figure 2 in [1]}). Hence, there exists a tradeoff between concept and task loss while using joint or sequential training paradigm. However, as we will demonstrate in Tables REF , REF  and REF , joint training shows higher vulnerability of concepts to malicious attacks - implying that concepts learned during joint training are less robust as compared to those learned in sequential. This behavior is expected - as concepts learned during joint training have higher chances of being spuriously correlated to predictions, making them easier to be maliciously attacked.
